Perspective Functions

void persp_0 (const real front_corner_x, const real front_corner_z, const real side_lft, const real side_rt, const real angle_rt, const real f_2_cv, const real gl_2_cv, [const real horizon_lft = 6, [real horizon_rt = 0, [real gl_lft = 0, [real gl_rt = 0]]]])

Function

Defined in utility.web. This function is used for the figure in The Perspective Projection, illustrating a perspective projection as it could be done by hand. It draws a rectangle in the ground plane and the construction lines used for putting it into perspective. It also labels the vanishing and measuring points. The arguments: const real front_corner_x The x-coordinate of the front corner of the rectangle. const real front_corner_z The z-coordinate of the front corner of the rectangle. const real side_lft The length of the left side of the rectangle. const real side_rt The length of the right side of the rectangle. const real angle_rt The angle at which the right side of the rectangle recedes to the horizon. const real f_2_cv The distance from the focus to the center of vision. const real gl_2_cv The distance of the ground line to the center of vision. const real horizon_lft Default: 6. The length of the horizon line leftwards of the center of vision. real horizon_rt Default: 0. The length of the horizon line rightwards of the center of vision. real gl_lft Default: 0. The length of the ground line leftwards of the line from the focus to the center of vision. real gl_rt Default: 0. The length of the ground line rightwards of the line from the focus to the center of vision. Example: persp_0(3, 2, 10, 5, 47.5, 7, 5, 8.5, 9.5, 8.5, 9.5); Fig. 199.